1. Field of the Invention
The present invention relates to a measurement system including a robot and a machine tool.
2. Description of the Related Art
To improve a precision of positioning over an entire range of operation of an industrial use multi-articulated robot, it is known to automatically calibrate the mechanical parameters.
Japanese Patent Publication No. 2008-012604 discloses a method of using a light receiving device recognizing a target so as to automatically measure a relationship between a front end position of a robot and displacement of a controllable drive axis and to find dimensional error of component parts and amounts of their elastic deformation and other error that can be formulated. Further, Japanese Patent Publication No. 2008-012604 describes to realize improvement of precision over the entire range of operation of a robot by setting a plurality of targets and performing the measurement a plurality of times for the targets.
When setting a plurality of targets within the range of work of a robot and performing measurement a plurality of times for the targets for the purpose of uniformly improving the precision of positioning in the range of work of the robot, it is necessary to add the errors of the different target positions to the parameters to be identified and calculated. For this reason, it is necessary to increase the number of times of measurement along with the increase in the number of targets set. For example, in the invention described in Japanese Patent Publication No. 2008-012604, if the positions of the targets to be measured increase by 1, the error parameters of the target positions increase by 3. If increasing the measurement positions and postures by 1, the number of formulas able to be utilized for identification and calculation increases by 3, so to deal with the increase in error parameters, every time increasing the positions of the targets by 1, it is necessary to increase the measurement positions and postures by 1.
Japanese Patent Publication No. 2005-201824 also describes related art.